#ifndef PARSER_H_62B23520_7C8E_11DE_8A39_0800200C9A66
#define PARSER_H_62B23520_7C8E_11DE_8A39_0800200C9A66

#if defined(_MSC_VER) ||                                            \
    (defined(__GNUC__) && (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || \
     (__GNUC__ >= 4)) // GCC supports "pragma once" correctly since 3.4
#pragma once
#endif

#include <ios>
#include <memory>

#include "yaml-cpp/dll.h"

namespace YAML {
class EventHandler;
class Node;
class Scanner;
struct Directives;
struct Token;

/**
 * A parser turns a stream of bytes into one stream of "events" per YAML
 * document in the input stream.
 */
class YAML_CPP_API Parser {
public:
    /** Constructs an empty parser (with no input. */
    Parser();

    Parser(const Parser&) = delete;
    Parser(Parser&&) = delete;
    Parser& operator=(const Parser&) = delete;
    Parser& operator=(Parser&&) = delete;

    /**
     * Constructs a parser from the given input stream. The input stream must
     * live as long as the parser.
     */
    explicit Parser(std::istream& in);

    ~Parser();

    /** Evaluates to true if the parser has some valid input to be read. */
    explicit operator bool() const;

    /**
     * Resets the parser with the given input stream. Any existing state is
     * erased.
     */
    void Load(std::istream& in);

    /**
     * Handles the next document by calling events on the {@code eventHandler}.
     *
     * @throw a ParserException on error.
     * @return false if there are no more documents
     */
    bool HandleNextDocument(EventHandler& eventHandler);

    void PrintTokens(std::ostream& out);

private:
    /**
     * Reads any directives that are next in the queue, setting the internal
     * {@code m_pDirectives} state.
     */
    void ParseDirectives();

    void HandleDirective(const Token& token);

    /**
     * Handles a "YAML" directive, which should be of the form 'major.minor'
     * (like a version number).
     */
    void HandleYamlDirective(const Token& token);

    /**
     * Handles a "TAG" directive, which should be of the form 'handle prefix',
     * where 'handle' is converted to 'prefix' in the file.
     */
    void HandleTagDirective(const Token& token);

private:
    std::unique_ptr<Scanner> m_pScanner;
    std::unique_ptr<Directives> m_pDirectives;
};
} // namespace YAML

#endif // PARSER_H_62B23520_7C8E_11DE_8A39_0800200C9A66
